1. Field of the Invention
This invention relates to a rack and pinion steering gear assembly, and to a method of manufacturing a rack and pinion steering gear assembly.
2. Prior Art
A rack and pinion steering gear assembly is used to turn the steerable wheels of a vehicle and includes a rack mounted for axial movement in a rack housing. A pinion gear drivingly connected with the steering wheel projects into the rack housing. The teeth of the pinion gear engage teeth on the rack. In a non-power assisted rack and pinion steering gear assembly, turning the steering wheel causes the pinion to turn, which directly causes the rack to move. In a hydraulic power assisted rack and pinion steering gear assembly, when the steering wheel is turned a hydraulic valve is actuated and fluid is directed to a hydraulic motor which moves the rack. The pinion is rotated by the rack in a follow-up manner to return the hydraulic valve to neutral as the wheels turn. In the event of a failure in the hydraulics, when the steering wheel is turned, the rack moves axially because of the meshing engagement of the teeth of the rack and pinion.
Rack and pinion steering gear assemblies are of two basic types, "end take-off" and "center take-off". An end take-off assembly has portions of the rack bar protruding from opposite ends of the housing. The steerable wheels of the vehicle are connected, via appropriate linkage, one to each such end portion. Upon turning of the steering wheel, the end portions of the rack bar move, thus causing movement of the steering linkage connected thereto to steer the vehicle A center take-off rack and pinion steering gear assembly has both steerable wheels connected via appropriate linkage to one portion of the rack at a point intermediate the ends of the rack.
Few components of a typical center take-off rack and pinion steering gear assembly are interchangeable with those of a typical end take-off rack and pinion steering gear assembly. Therefore, separate and different tooling and parts inventories are required to manufacture a center take-off rack and pinion steering gear assembly and an end take-off rack and pinion steering gear assembly.